1. Field of the Invention
This invention relates to and has among its objects the provision of novel casting and splinting packages and novel methods for their construction. It is a particular object of the invention to provide a packaged casting or splinting material that may be immersed in water and then contacted with and formed about the body part to be immobilized or supported, whereupon it will become rigid and immobilizing or supporting in a short period of time. Further objects of the invention will be evident from the following description wherein parts and percentages are by weight unless otherwise specified.
2. Description of the Prior Art
Until recently, plaster of Paris casting materials have been employed almost exclusively in the orthopedic field to secure immobilization or support. However, polymeric resin casting materials have been disclosed in U.S. Pat. Nos. 3,373,741, 3,048,169, 3,630,194, 4,134,397, 4,214,578, and 4,231,356 and in German Patent Nos. 2,357,931 and 2,651,089. In usual practice a flexible carrier or substrate is coated or impregnated with a curable or settable composition, such as plaster of Paris or a polymeric resin. The substrate is selected generally from woven or knitted fabrics or non-woven webs made of natural or synthetic organic or inorganic fibrous materials. Strips of coated or impregnated substrates are activated and applied to the body part to be immobilized or supported after covering the body part with a soft cloth.
In U.S. Pat. No. 3,900,024 (hereinafter '024) there is disclosed an improved plaster cast and method of preparing it. In '024 a casting blank is prepared by placing a first sheet of deformable, water absorptive material on a supporting surface. A plurality of plaster splints are aligned on the above sheet. A second sheet of the same deformable, water-absorptive material as employed for the first sheet is placed over the first sheet to sandwich the plaster splints between the two sheets. The edge of the first and second sheets are bonded together to enclose the plaster splints therebetween. In use the '024 casting blank is saturated with water and then shaped about the body part to be immobilized or supported; securing means are used to hold the casting blank in place while it dries.
A plastic splint is disclosed in U.S. Pat. No. 3,373,741 (hereinafter '741). The '741 splint comprises a padded, sealed envelope containing at least two separate and distinct materials maintained separately. When the materials are mixed, a cured plastic resin composition is formed. In one embodiment of the '741 splint, the envelope also contains in a third compartment a reinforcing mat composed of a woven, knitted, or matted textile such as fiberglass, nylon, Dacron, cotton or Orlon. The lower portion of the envelope has a flexible pad secured thereto to prevent irritation of the patient and insulate the patient against heat liberated during the curing process. The flexible pad can be made of one-quarter inch polyurethane foam adhesively bonded to the envelope. The envelope can be formulated from a number of commercially available packaging films which are insoluble in, non-reactive with, and non-permeable to the uncured resin components. A polyester, epoxy, or polyurethane resin system may be used in the '741 splint.
In the use of the '741 splint, the separated components of the uncured resin system are mixed together while sealably confined in the envelope, and then the mixed components are contacted with the reinforcing mat in order to impregnate the mat. Next, the splint is placed in contact with the body part to be immobilized or supported and formed to the desired shape. The splint is held in place by means of straps or the like. Generally, the resin system will cure within ten minutes although longer times may occur depending on the resin system chosen.
Other casts and splints are disclosed in U.S. Pat. Nos. 3,656,475 and 3,674,021.
The known casting or splinting packages are disadvantageous because they are either cumbersome to manufacture or to apply or they are cumbersome to the patient who must wear the casting or splinting package.